Stem cells are a class of primitive cells with self-renewal capacity and multi-directional differentiation potential, including embryonic stem cells, adult stem cells and induced pluripotent stem (iPS) cells. Stem cells have a very important theoretical research significance and clinical application value. Using the embryonic stem cells to establish in vitro differentiation systems of a variety of cell types enables people to study the development process of mammals at the levels of cells and molecules; comparing gene transcription and expression of the embryonic stem cells with the stem cells and differentiated cells at different developmental stages can determine the molecular mechanism of embryo development and cell differentiation, meanwhile new genes can be discovered; the research of stem cells provides a new research means for the pharmacology, pharmacodynamics, toxicology, pharmacokinetics and the like of new drugs, overcoming the difficulty that the above experiments cannot be carried out directly in human body, meanwhile improving the effectiveness and safety of drug uses. Stem cells also have important applications in regenerative medicine, and the application of stem cells in the regenerative medicine involve all tissues and organs of human body, and also relate to most of medical problems faced by the mankind, such as cardiovascular diseases, diabetes, Parkinson's disease, cancer, Alzheimer's disease, autoimmune diseases, severe burns, spinal cord injury, hereditary diseases, osteoporosis, aging and so on.
In regenerative medicine, stem cell transplantation therapy has become an important means for the treatment of diseases, such as cell transplantation, organ transplantation and so on. Cell transplantation therapy is to transplant healthy stem cells into a patient's body, to repair or replace injured cells or tissues, so as to achieve the purpose of cure. Organ transplantation therapy takes stem cells as “seeds” to be subjected to directional induced differentiation in vitro to form desired tissues and organs, so as to replace the diseased tissues and organs. To use the stem cells in clinical treatment, first of all there must be sufficient sources, for example, the stem cells are generally required to be 1-4×106/kg body weight for adult transfusion, while the content of the stem cells in each part of cord blood is only 1×107 or so, therefore the current treatment is merely limited to children. The clinical application shows that the greater the input amount, the more the successful homing after transplantation, and the greater the probability of long-term rooting and reproduction. However, the stem cells in mammals have a very small number and tend to spontaneously differentiate, thus it is quite difficult to culture them in vitro for a long period of time in a large number. If the obtained rate of the stem cells can be tried to be improved during the process of in vitro isolation and culture, it will undoubtedly open up broad prospects for clinical applications of the stem cells.
Although growth factors and bioactive proteins can act as regulating drugs of stem cells, growth factors and bioactive proteins as macromolecular active substances, can intervene in the crisscross physiological processes in body, exhibit extremely complex multiple regulating functions, and are expensive and hard to have medicinal and clinical therapeutic value. Therefore, the potential of small molecule compounds as stem cell regulating drugs has been increasingly attached significance to by people. The small molecule compounds as drugs or culture medium additives have their unique advantages: the small molecule compounds are easy to administrate, and also easy to withdraw after physiological functions are recovered; the small molecule compounds are easy to artificially synthesize and achieve industrialized production, and have a good prospect of medicinal use; the small molecule compounds, especially natural small molecule compounds, having undergone biological metabolic processes, possess good biocompatibility, especially fewer toxic and side effects. Therefore, to search for small molecule compound regulating agents for stem cells has become a research focus of stem cell drugs.